World's biggest and smallest CT scanner

A scanner large enough to accommodate cars and plane wings together with a portable device a size of a microwave oven has been developed by German scientists.

The XXL CT scanner, developed to examine contents of shipping containers, consists of a giant turntable and an X-ray source, moving up and down alongside the studied object.

The movements of the source are mirrored by a four-meter-long X-ray detector on the opposite side of the turntable.

“We have never been able to carry out non-destructive material testing on this scale before,” said Professor Randolf Hanke, director of the Fraunhofer Development Centre for X-ray Technology (EZRT).

Using a computer technology, the system generates 3D images with a resolution of up to 0.8mm, allowing displaying detailed images of objects several metres in size.

The team would like to eventually increase the resolution to up to 0.4mm.

The system can be used to examine prototypes of transportation vehicles or their parts, detecting the tiniest faults and cracks in the components.

Security forces could use the scanner to detect explosives or other prohibited objects in shipping containers without having to open them.

Another team at the EZRT has created a counterpart to this device, building the smallest portable CT scanner in the world. A size of a microwave oven, the scanner creates images with a resolution of 0.02mm – enabling scanning minuscule plastic parts or biological samples.

The team is already aiming to achieve scales even smaller – down to 100 of nanometres.

“We’ve now succeeded in customizing an electron microscope in such a way that it is able to produce a nano X-ray source,” Hanke explained.

The system relies on electric charge carriers generating the X-rays, which are conducted onto the side of a thin needle. The resulting X-rays emitted from the tip of this needle deliver a precise focal point 50nm in diameter for scanning nano-scale objects in clearly defined detail.

This technology would, for example, allow biologists to analyse how water is transported within wood fibres.